A Queens man convicted of defrauding distressed homeowners in a mortgage scam is seeing his own Howard Beach home overrun by squatters while he’s sitting in the clink.

Neighbors of the two-story house worth $562,000 on 90th Street say the brazen interlopers have been bounced and arrested — but they keep coming back.

“Who are they, and where did they come from?” fumed one resident, adding that one squatter laughed when police cuffed him last week. “When the cops came, he had no shame.”

The house’s owner, Isaak Khafizov, 27, was sentenced to nine years in federal prison last month for bilking people out of hundreds of thousands of dollars after promising to get their mortgages modified and lower their monthly payments. Instead, he just pocketed their cash, according to court papers, and many of his victims subsequently lost their homes to foreclosure.

Vicki Tepper, a victim of the scheme, said that with his new home woes, Khafizov was getting “what he deserves.”

“He messed with a bunch of people’s lives,” said Tepper, who owns a pet shop in New Jersey. “He took our money, and he tricked us into believing things that weren’t true.”

But neighbors care less about the poetic justice than about getting the bums out. Last week, one vigilante cut electricity to the home, and a front window was smashed.

Before that, one alleged squatter, Peter Zephyrin, sat in a lawn chair to taunt neighbors after he was arrested and released.

“These people are going nuts. Cuckoo!” Zephyrin, 35, said. “Calm down, relax. I work! I am not a criminal.”

Zephyrin claims he legally moved into the home in December, shortly after he supposedly responded to a Craigslist ad and met with Khafizov at a local Dunkin Donuts.

He presented The Post with what he said was a lease. The document was dated Dec. 1, 2013, and appeared to bear Khafizov’s signature.

It lists the monthly rent as $800, but Zephyrin said he paid $2,000 upfront and stays rent-free in exchange for fixing up the home.

Such an arrangement would have been impossible, since Khafizov has been locked up since May 2012, according to his lawyer and Federal Bureau of Prisons officials.

“I can categorically tell you there’s no way on earth that [Khafizov] was out of jail in December 2013,” said attorney James Kousouros.

Neighbors say that Khafizov and his girlfriend lived in the home until he was sent to prison and that the house has been vacant as far back as Hurricane Sandy, which hit five months later.

Assemblyman Phillip Goldfeder (D-Queens) said a bank has repossessed the home and plans to take legal action to remove the squatters.

“The most ironic part is the guy went to prison for mortgage fraud, and now his home has been a hub for criminal activity,” Goldfeder told The Post.

Khafizov’s company, American Home Recovery, promised to reduce people’s mortgage payments, but he disappeared after taking their money, which he spent on his own mortgage, a Mercedes and credit-card bills, documents show.